Fragment production in high energy proton-nucleus collisions

The experimental situation is reviewed, and the theoretical results on production of light fragments (p, α, t, 3He, 4He, 6Li) in collisions of high energy hadrons and nuclei with nuclei are outlined. Manin attention is given to production of comparatively fast fragments outside the evaporation region. The processes related to cumulative hadron production on nuclei are considered. Intensive recent studies on deep inelastic processes of nucleus-target fragmentation under the effect of 1-400 GeV particles (p, π+-, γ-quanta) and nuclei (d, He, C, Ne, Ar) allowed one to reveal some regularities in nuclear processes such as cumulative effect, nuclear scaling. In all experiments a strong A-dependence of inc lusive cross sections of the formation of cumulative fragments is observed. In the cumulative region (back hemisphere) the main contribution to the inclusive process cross section is given by the spectator mechanism and cumulative mechanisms with and withour rescattering. Preliminary evaluations show that the account of rescattering plays a decisive role in the explanation of the observed angular dependence of inclusive cross sections